Toshiba 32AV502R

[Vizor]

Model: Toshiba 32AV502R
Issue: Picked this tv up for 15$ worked one day and next didn't or so i was told

Symptoms: When Fully Powered down and turned back on Power comes on, very top of the screen tries to light up very very very quick and dim green light is flashing on the TV and doesn't stop flashing.

All voltages are outta whack hear noises coming from the power board here where i have a video to help.

163.8 coming off the main cap when powered on however.

http://www.youtube.com/watch?v=KU6opm7Tdd0

[retiredcaps]

Re: Toshiba 32AV502R

163.8 coming off the main cap when powered on however.

1) What is the DC voltage across the startup cap, C207 (right by the SP2)? Is it steady or fluctuating?

2) What is the SMPS IC part number right by the startup cap?

[Vizor]

Re: Toshiba 32AV502R

1) What is the DC voltage across the startup cap, C207 (right by the SP2)? Is it steady or fluctuating?

Voltages all over the place unstable.

2) What is the SMPS IC part number right by the startup cap?

CHN
Viper27L
KV3848

[retiredcaps]

Re: Toshiba 32AV502R

1) What is the DC voltage across the startup cap, C207 (right by the SP2)? Is it steady or fluctuating?

Voltages all over the place unstable.

If you have an ESR meter, check the startup cap, otherwise try replacing the startup cap first, it is the easiest.

[retiredcaps]

Re: Toshiba 32AV502R

Viper27L

1) Refer to figure 3

https://cdn.badcaps-static.com/pdfs/...9c18eaaac3.pdf

2) See if GND is shorted to VDD (pin 1 to 2).

3) Measure the DC voltage on pin 2 (using pin 1 as GND). Be specific in the range that it is wildly fluctuating.

[retiredcaps]

Re: Toshiba 32AV502R

1) What is the DC voltage across the startup cap, C207 (right by the SP2)? Is it steady or fluctuating?

Voltages all over the place unstable.

Be specific in the range that it is unstable. With your above description, I have no idea if is unstable between 1V and 166V.

If your multimeter has min/max, use to see what the lower and upper range.

[Vizor]

Re: Toshiba 32AV502R

Replaced C207 and no change. the blueish thing next to the transformer is the biggest noise i hear PHSl04J 800VHoB

[Vizor]

Re: Toshiba 32AV502R

Be specific in the range that it is unstable. With your above description, I have no idea if is unstable between 1V and 166V.

If your multimeter has min/max, use to see what the lower and upper range.

5.34v
max 13.46v

[Vizor]

Re: Toshiba 32AV502R

5.34v
max 13.46v

same thing on the IC also.

[tom66]

Re: Toshiba 32AV502R

Check the resistor and diode feeding off the transformer for the cap (on primary side.)

Check all diodes on secondary for shorts.

[retiredcaps]

Re: Toshiba 32AV502R

same thing on the IC also.

On page 6 of the pdf, the VDDon is 14V DC typical. The minimum is 13V and max is 15V. So it looks like the SMPS IC is trying to start if the max is 13.46V DC. This is why the actual readings are critical.

Since you changed the startup cap, this means that there is probably a shorted diode on the board causing the SMPS to startup, shutdown, startup, shutdown, etc.

I see at least two diodes right by the startup cap, possibly 3. There is also another underneath the big yellow transformer. Test them all and others that you find with your diode test function. If one is shorted, it will give the same reading in both directions.

If you cannot find a shorted diode, then the SMPS is the next suspect which is why I asked you to check for a short between GND and VDD.

edit: Ahh, tom66 beat me while I was reading the datasheet.

[Vizor]

Re: Toshiba 32AV502R

TVS1 Dead/Zero nothing.

[Vizor]

Re: Toshiba 32AV502R

D500 is Bad and D203 is Open

[tom66]

Re: Toshiba 32AV502R

TVS1 is a surge protection device - it is normal for it to appear open circuit on a typical test.

However D500 is probably the fault if it appears short circuited. Does it?

D203 -> could be faulty, but please remove it and read off the part # so we can tell if it is a TVS or otherwise.

[Vizor]

Re: Toshiba 32AV502R

Small one: PS!010R Dec 9019

Big one: 09016 SB540

[Vizor]

Re: Toshiba 32AV502R

Can't seem to find them on Digi

[S2udio]

Re: Toshiba 32AV502R

Maybe these
If you can decrypt the right one
https://cdn.badcaps-static.com/pdfs/...cccfb3af1d.pdf,
and this for the big one,
https://cdn.badcaps-static.com/pdfs/...f3ff9c0fdf.pdf.
Both readily available

[selldoor]

Re: Toshiba 32AV502R

@s2udio2
"Most of the time things ain't what they seem to be "

You may be correct but why isn't the small one ( PS!010R) of these:

https://cdn.badcaps-static.com/pdfs/...9c194b055a.pdf

[Vizor]

Re: Toshiba 32AV502R

lol i have no idea what they are either i just wrote down what i see.

[budm]

Re: Toshiba 32AV502R

That D203 may be the Snubber diode (about 200V rating) which in parallel with the primary winding of the transformer, it will read low Ohm due to the low DC resistance of the winding. Verify if the Diode is in parallel with the transformer winding.